Chemical components of Dendrobium crepidatum and their neurite outgrowth enhancing activities

15 compounds, including two new ones crepidatuols A (1) and B (2) were isolated from the stems of Dendrobium crepidatum. The planar structures of these compounds were elucidated by spectroscopic methods (NMR, MS, UV, and IR) and comparison with those from literatures. 10 compounds were send for enhancing activities on nerve growth factor (NGF) medicated neurite outgrowth in PC12 cells and the results indicated that crepidatuol A (1), confusarin and 3-(2-acetoxy-5-methoxy)-phenylpropanol showed enhancing activities at the concentration of 10.0 μM.